Various processes have been used for the sanitization and packaging of meat using ozone. For example, meat has been packaged in a sealed container while the product is exposed to an oxidizer such as O.sub.3, F.sub.2, Cl.sub.2, Br.sub.2, I.sub.2, H.sub.2 O.sub.2, KMnO.sub.4, HOBr, HOCl, ClO.sub.2, or O.sub.2. Additional oxidizer is then added to increase its concentration and/or to bring the pressure above 1 atmosphere. In another prior process, animal flesh has been mixed with water in contact with ozone. The ozone is injected into the water at a pressure of, for example, 5 kPa through diffusers placed evenly throughout a hollow tube. Processes for using ultraviolet radiation, which produces ozone, to reduce microbial contamination of meat have also been described.
Another prior process of processing meat involves exposing the meat to a vacuum before and after treatment with a sanitizing agent such as steam, ozone, hydrogen peroxide, or propylene oxide. An apparatus and method for sterilizing and chilling animal carcasses has also been proposed whereby poultry is treated with ozonated water.
Processes involving the use of ozone have also been disclosed for treatment of food products in general. One such process has been disclosed in which food products, such as fragile vegetables, are treated in an elongated housing structure filled with ozone. Ozone is distributed from a source, such as a pressure vessel, at spaced locations.
Another prior process has been described in which food products are introduced into a liquid bath that has a plurality of ozone-air bubbles continuously streaming through the liquid such that the bubbles interface with the surface of the food products. In one aspect, a gaseous mixture of ozone and air is introduced into a liquid bath in a manner which creates a multitude of ozone-air bubbles in the bath. In a second aspect, the gaseous ozone-air mixture is first mixed with a quantity of liquid of the bath, followed by injection of the combined, aqueous mixture into the bath to form a multitude of ozone-air bubbles.
Yet another process for sterilizing foodstuffs has been described, whereby the foodstuffs are sterilized in a processing room, packing receptacles, or a refrigerator by use of a mixture of ozone gas and carbon dioxide gas and/or nitrogen gas.
Ozone is one of the most powerful oxidizers available. Due to its propensity to oxidize substances, it is very difficult to transport ozone from its site of generation to the application point. Furthermore, ozone cannot be stored for an appreciable length of time. For example, at atmospheric pressure at 86.degree. F., ozone will decompose in about one week. And ozone decomposes more quickly as pressure is increased.
Because of the aforementioned properties of ozone, improvements are needed in current methods for using ozone in the sterilization of food so that the sterilization process will take place more effectively. Such improvements are the focus of the present invention.